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Gatehouseite
Gatehouseite is a manganese hydroxy phosphate mineral with formula Mn5(PO4)2(OH)4. First discovered in 1987, it was identified as a new mineral species in 1992 and named for Bryan M. K. C. Gatehouse (born 1932). , it is known from only one mine in South Australia. Description Gatehouseite occurs as radiating or divergent groups of bladelike crystals up to 100 μm by 20 μm by 5 μm in size and as overgrowths on arsenoclasite that are up to 5 mm long. The transparent mineral can be brownish-orange or yellow in color. Gatehouseite is the phosphorus analogue of arsenoclasite. The mineral occurs in cavities in sedimentary iron and manganese deposits in association with arsenoclasite, shigaite, hematite, hausmannite, triploidite, barite, and manganoan ferroan calcite. Based on a 1977 experiment that produced triploidite, it is likely that gatehouseite formed by a reaction between hausmannite and basic phosphorus-rich fluids at low temperature and variable pH conditions. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arsenoclasite
Arsenoclasite (originally arsenoklasite) is a red or dark orange brown mineral with formula Mn5(AsO4)2(OH)4. The name comes from the Greek words ''αρσενικόν'' (for arsenic) and ''κλάσις'' (for cleavage), as arsenoclasite contains arsenic and has perfect cleavage. The mineral was discovered in 1931 in Långban, Sweden. Description Arsenoclasite is red or dark orange brown in color. The mineral rarely occurs as crystals; rather it has either a massive or granular habit. When crystals are present, they are no larger than . Arsenoclasite has been found in association with adelite, allactite, barite, calcite, dolomite, gatehouseite, hausmannite, hematite, manganoan ferroan calcite, sarkinite, and shigaite. The mineral occurs in fissures of metamorphosed Fe- Mn ore bodies and sedimentary Fe-Mn deposits. Structure A 1971 study identified the mineral's structure as an array of oxygen atoms in a double hexagonal close packed pattern. However, a 1977 study discovered th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |